The ion migration spectrometry (IMS) is a rapid, sensitive and portable on site inspection technique. Such technique has already been applied in the military and security agencies, which can inspect toxic chemical agent, explosive and drugs and so on. In order to eliminate the interference and improve the inspection sensitivity, when the ion mobility spectrometry is used to inspect the contraband articles, it usually requires introducing a small amount of polychlorocarbon toward and into the ionized chamber of the migration tube, so that the polychlorocarbon is preferentially ionized under the action of the ion source. Thus, on one hand, it competes with the interference to reduce the ion concentration of the interference, accordingly, it helps to reduce the disturbance; on the other hand, it is able to transfer the ionic charge to the molecule of the article to be inspected, so that the ion concentration of the article to be inspected is greatly increased, thus the response signal of the article to be inspect, that is, the inspection sensitivity of the instruction is improved.
As a dopant substance, whether a liquid substance such as methylene chloride and the like or a solid substance such as hexachloroethane and the like, there is always a certain quantity of liquid molecules for keeping the balance with the dopant substance under the normal temperature and pressure (NTP), such molecules are the dopant gas to be used for improving the performance of the ion mobility spectrometry instrument. Apparently, different dopant substances, specifically, dopant substances in different states, contains the gaseous molecules with different concentration in the air under the same condition. In a general way, the vapor pressure of the liquid substances is much greater than the gas pressure volatilized from the substances in solid state. When the inspection items are different, the dopant to be used and the states thereof are different, and conditions for producing the dopant gas are different too. When the liquid dopant is used, the tightness of vessel for containing the dopant should be good. It shall be ensured that not only the dopant will be not overflowed and sprinkled during the usage and the operation of the device, but also the dopant gas can be produced smoothly and exuded in thimbleful. When the dopant in the solid state is used, it may also require heating the dopant to increase the production quantity of the dopant gas.
Presently, there is no dopant gas generating device meeting both of the above requirements well at the same time. Thus, it has been a demand to provide a dopant gas generating device, in which not only a solid state dopant, but also a liquid state dopant can be used, it also can adjust the generating quality of the dopant gas.